IMAP claims that I have an invalid user, why? Imap is currently only functional when used with the main user mail account (also known as the catch all) . Sub-mail accounts cannot use the IMAP feature. The username and password must use the following syntax user : mainuser pass : mainpass It cannot use the following syntax user : user@yourdomain.com pass : pass If you have any suggestions for or problems with this website, please e-mail support@mercuryd.com